Simultaneous　catalytic　elimination　of　NO　and　N2O　from　exhausts　is　an　ideal　solution　for　nitric　or　adipic　acid　plants.　Herein,　Fe　-based　zeolite　catalysts　were　applied　for　the　NH3-NOx-N2O　system.　1%　Fe-SSZ-13　performed　excellent　catalytic　activity　with　100%　conversions　for　both　NOx　and　N2O　at　400-600　degrees　C.　Experimental　and　computational　research　studies　unraveled　that　NO　could　significantly　improve　N2O　decomposition　by　reacting　with　alpha　O*　to　generate　easily　desorbed　NO2;　furthermore,　NO-alpha　O*　also　can　decrease　charge　density　of　Fe-alpha　O*,　facilitating　alpha　O*　desorbed　from　the　Fe　sites.　Besides,　NH3　inhibits　low-temperature　deN2O　activity　due　to　strong　competitive　adsorption　with　N2O;　however,　NH3　accelerates　N2O　decomposition　by　consuming　alpha　O*　and　simultaneously　reduces　N2O　as　a　reductant　at　high　temperature.　Interestingly,　the　alpha　O*　generated　from　N2O　decomposition　would　enhance　NO　oxidation　to　NO2,　which　is　beneficial　to　NH3-selective　catalytic　reduction.　This　work　elaborates　fundamental　insights　for　simultaneous　abatement　of　NOx　and　N2O　and　provides　candidate　catalyst　for　application.